[Suggestion] Round not found could use next and prev

[JJRcop]

When I'm cycling through the rounds going backwards down the history using the next and previous buttons on the round page, whenever I hit a round that doesn't exist I have to edit the number in my browser's address bar until I get back to the valid rounds.

It would be nice to have next and previous buttons on this page to make this easier. I don't think they should check for validation, just be dumb buttons that decrease/increase the round ID like the ones on the round page do now.

[nfreader]

That should be easy enough to implement